Cramer: Can rally catalysts drive advance further?

With the market in a fierce tug of war between bulls and bears, pros such as Jim Cramer often go beneath the rally to determine which catalysts actually drove the advance and then attempt to determine whether those forces can endure.

Here's what Jim Cramer says drove the rally on Monday.

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1. M&A:Endurance Specialty bid to take over Aspen Insurance Holdings while TIAA Cref announced the $6.5 billion acquisition of Nuveen.

Although Aspen later spurned the offer, that's not what matter, Cramer said, noting that M&A is the mother's milk of a rally. Not only does the activity suggest there's value in the market, it could take supply out of the market, he said. And considering all the recent IPOs, Cramer thinks a decline in supply is sorely needed.

"This upgrade resonated with investors and took many a credit card issuer with it," Cramer said, reminding the market that there's value in the financial sector.

3. Solid quarter from Citigroup: "Here's a bank that just got rejected by the authorities for its plans to return capital, including dividends and buybacks. Yet, the reported numbers were so good that you have to believe Citi can get approval at least some day," Cramer said.

Also, Citi's earnings were relatively strong, and that means others may be good, too. "So far we're three for four with major earnings numbers, Citigroup, Alcoa and Wells Fargo to the good and JPMorgan to the bad. You keep that ratio and this rally's got legs."